Molecularly Stacking Manganese Dioxide/Titanium Carbide Sheets to Produce Highly Flexible and Conductive Film Electrodes with Improved Pseudocapacitive Performances

2D nanostructures with high surface area and flexibility are regarded as a promising building platform for flexible supercapacitors that are attracting tremendous attention due to their potential applications in various wearable technologies. Notably, although pseudocapacitive metal oxides are widely accepted as a very important class of electrochemically active materials, the utilization of 2D metal oxide sheets in the preparation of flexible supercapacitors is very rare. The scarcity of a suitable filler with the integrated properties of both high conductivity and excellent hydrophilicity is probably to blame. In this work, by introducing a recently discovered intriguing material, Ti3C2 sheets, a novel MnO2/Ti3C2 hybrid with a molecularly stacked structure is developed using a simple and scalable mixing and filtration method. Their individual advantages are combined in the hybrid, thus delivering excellent electrochemical performances. A highly flexible and symmetric supercapacitor based on the novel hybrid electrode manifests top-class electrochemical performance with maximum energy and power densities of 8.3 W h kg(-1) (at 221.33 W kg(-1)) and 2376 W kg(-1) (at 3.3 W h kg(-1)), respectively, regardless of the various bending states, suggesting enormous possibilities for applications in future flexible and portable micropower systems.